Ammo Nomenclature / Ammo 101

[luckyc1423]

I am pretty new into shooting and when you go to the store to buy ammunition it can be very confusing.

I have done some research online and I have compiled a list below. I have done this more so the experienced shooters can inform me if I understand everything properly, and maybe it will help out some inexperienced forum members like myself.

Please let me know what is wrong below and I will make the corrections just incase someone else like me stumbles across this thread. (I researched threads and couldnt find exactly everything in one place).

Again I am writing this so to help myself better understand ammo terminology and have experienced users correct me in areas were i might be thinking wrong.



Ammo 101

basic components of ammo are the 1) casing, 2) the powder or charge that is held within the casing, 3) the bullet or projectile that sits on the casing.

1) Casing --> Steel or Brass Option. Steel ammo is cheaper to purchase vs Brass. The main issue with Steel is it doesnt expand to plug the barral as quickly as Brass, this basically means that since steel is not expanding as quickly you get more gun powder residue sliding passed the casing and going into the rest of the gun. Thus making the gun dirtier.
So essentially the biggest difference between brass and steel is that steel will make your gun dirtier, thus making the gun more difficult to clean

2) Ammo Powder/Charge --> If you are looking at one caliber, lets say 9mm, all manufactures/bullets will essentially have the same amount of charge/powder. Unless the box designates a +P or a +P+. ........ +P stands for higher pressured ammunition than normal. +P+ is a step above +P
For target practicing standard ammunition is fine. But if you are shooting a really large grain bullet then a +P+ would be befinicial since the bullet weighs more.
So for a random example (no clue if this is true but this is just for understanding purposes)
A 115 grain bullet flies faster than a 124 grain bullet. But if you had a +P 124 grain bullet then it might fly at the same speed as a 115 grain bullet with a standard powder/charge.
So think of it like this
115 grain standard power flies at the same speed as a 124 grain bullet at +P power which flies at the same speed as a 160 grain bullet at +P+ power
Again no idea if the above is true but just used those examples to demonstrate +P

3a) Projectile Grain --> This refers to the weight of the bullet (projectile). 115 grain being a slightly smaller/lighter projectile than 124 grain. The smaller the grain the faster the projectile with everything else being equal. The bigger the grain the more knock down power (more mass hitting the target)

3b) Projectile FMJ --> stands for full metal jacket. this means the bullet/projectile is covered in a thicker copper or thicker material than the bullet is made out of. The only part of the bullet that is not covered in this thicker copper material is the bottom of the bullet
Basically the benefit of FMJ is to prevent the lead projectile/bullet from having small particles of the bullet go into the air at the range.


3c) Projectile TMJ --> stands for total metal jacket. This is basically the same thing as FMJ except with TMJ the bottom of the bullet is also covered in the copper material


3d) Projectile tip types --> Rounded vs. hollowpoint vs polymer tips --> rounded is best for target as it is cheaper. Hollowpoint is a hunting or defense round that expands when it hits a target creating more damage. Polymer tip is essentially a hollowpoint tip except the hollow part is cover in a polymer material so it will fly straighter in the air. But once it hits its target the polymer material goes away and now the bullet is a hollowpoint and will do the same damage as a hollowpoint buller


So when you are at cabellas or walmart buying ammunition you will see it like this

Caliber/Gun Size --> Grain size --> and whether it is a FMJ or TMJ

So for example

9mm --> 124 grain --> FMJ

Then you just have to read the box to figure out what type of casing it has.

If you open the box and look at the ammo and its a shiny bronze color then it is probably brass. If it is a gray color then it is probably steel.

So, for all intensive purposes if 1 bullet has the exact same ratings it doesnt matter which manufacturer you choose because the bullets will be pretty close to the same. So either choose the manufacturer that you favor or choose the cheapest manufacturer since the bullets should perform the same.

 

[Cheapshooter]

A good start on your education.

1) Casing --> Steel or Brass Option. Or aluminum in the case of CCI Blazer ammo. Lower cost, one time use (not reloadable). There are said to be other differences in steel case ammo. Such as premature extractor wear in the gun. Also, sometimes the lacquer applied to prevent rust can get soft, and sticky.

2) Ammo Powder/Charge --> If you are looking at one caliber, lets say 9mm, all manufactures/bullets will essentially have the same amount of charge/powder. Not necessarily. In addition to the weight of the powder, the type of powder, it's burning rate, is also a variable. Some ammo may use less of a faster burning powder than another brand uses of a slower burning powder. You are right as to generally a lighter bullet factory load has a higher velocity than a heavier bullet in the same cartridge. Standard pressure, and +P is in reference to the standards listed by the Sporting Arms and Ammunition Manufacturers' Institute (SAAMI) +P+ is an even higher pressure non listed loading.

3a) Projectile Grain --> Correct, but lose the "knock down power" reference. There IS no such thing! However, the muzzle energy, the genetic energy of the bullet striking something is a combination of bullet weight and velocity. A lighter bullet at much higher velocity may have a higher muzzle energy than a heavier bullet at a much reduced velocity in the same cartridge.As to the knock down thing, that is an entire subject too long for this reply.

3b) Projectile FMJ --> FMJ ammo is our standard military ammo, and lower cost target ammo. Defense ammo is generally hollow point, hunting ammo hollow point, or soft point. In some smaller calibers for small pocket pistols FMJ is preferred because an expanding bullet may not have enough velocity to expand properly. Also, it may not penetrate deep enough to cause damage to vital organs, or the spinal cord.

3d) Projectile tip types --> Rounded vs. hollowpoint vs polymer tips --> And more! Add to them wad cutter, a type of target bullet that is basically a cylindrical slug with no nose, but rather just a flat front edge that cuts a meet round hole. Semi-wad cutter. As the name implies, a bullet with a sharp cutting edge, but a cone shaped nose with a base somewhat smaller than bore diameter leaving that edge to cut a round hole. These bullet types are generally of swagger pure lead, or cast of lead alloy, and have no copper jacket.

So, for all intensive purposes if 1 bullet has the exact same ratings it doesnt matter which manufacturer you choose because the bullets will be pretty close to the same. So either choose the manufacturer that you favor or choose the cheapest manufacturer since the bullets should perform the same. No, there still can be differences velocity, and other ballistic characteristics. For general target shooting, not much difference. But in defensive ammo there can be differences even in how reliable the ammo is in a particular gun.

Then you just have to read the box to figure out what type of casing it has. Steel case ammo is mostly if not entirely Russian made. It usually has names including an animal name. Wolf, Silver Bear, Brown Bear. Usually cheaper price than US ammo, and other European made ammo.

Some very good reading to increase your education.
http://www.gundigeststore.com/cartridges-of-the-world

 

[luckyc1423]

Thanks for the info!! See my questions to your remarks in red

1) Casing --> Steel or Brass Option. Or aluminum in the case of CCI Blazer ammo. Lower cost, one time use (not reloadable). There are said to be other differences in steel case ammo. Such as premature extractor wear in the gun. Also, sometimes the lacquer applied to prevent rust can get soft, and sticky.
Is CCI the only major company that does aluminum. What would be the advantage/dissadvantage of aluminum over steel or brass?

2) Ammo Powder/Charge --> If you are looking at one caliber, lets say 9mm, all manufactures/bullets will essentially have the same amount of charge/powder. Not necessarily. In addition to the weight of the powder, the type of powder, it's burning rate, is also a variable. Some ammo may use less of a faster burning powder than another brand uses of a slower burning powder. You are right as to generally a lighter bullet factory load has a higher velocity than a heavier bullet in the same cartridge. Standard pressure, and +P is in reference to the standards listed by the Sporting Arms and Ammunition Manufacturers' Institute (SAAMI) +P+ is an even higher pressure non listed loading.
Ok this can get confusing fast. In general, when I am selecting ammo at the store is this something I have to worry about "faster burning..ect.." Do they even list this on the box? How do I chose which is best? --> Is it best for general purposes to assume its standard? I get what you are saying that different companies use different powder types which can burn at different rates. I am just not sure if this is something that I would need to get wrapped up in since i wont ever be a competition shooter?

3a) Projectile Grain --> Correct, but lose the "knock down power" reference. There IS no such thing! However, the muzzle energy, the genetic energy of the bullet striking something is a combination of bullet weight and velocity. A lighter bullet at much higher velocity may have a higher muzzle energy than a heavier bullet at a much reduced velocity in the same cartridge.As to the knock down thing, that is an entire subject too long for this reply.
I will just put that this refers to the weight of the bullet. Lighter bullets fly faster..ect.

3b) Projectile FMJ --> FMJ ammo is our standard military ammo, and lower cost target ammo. Defense ammo is generally hollow point, hunting ammo hollow point, or soft point. In some smaller calibers for small pocket pistols FMJ is preferred because an expanding bullet may not have enough velocity to expand properly. Also, it may not penetrate deep enough to cause damage to vital organs, or the spinal cord.

3d) Projectile tip types --> Rounded vs. hollowpoint vs polymer tips --> And more! Add to them wad cutter, a type of target bullet that is basically a cylindrical slug with no nose, but rather just a flat front edge that cuts a meet round hole. Semi-wad cutter. As the name implies, a bullet with a sharp cutting edge, but a cone shaped nose with a base somewhat smaller than bore diameter leaving that edge to cut a round hole. These bullet types are generally of swagger pure lead, or cast of lead alloy, and have no copper jacket.
I will add these things, and do my research to learn more about these tip types. I think for common use for me atleast with my 9MM i will probably stick with round tip for target and hollow point for defense

 

[Aguila Blanca]

I get what you are saying that different companies use different powder types which can burn at different rates. I am just not sure if this is something that I would need to get wrapped up in since i wont ever be a competition shooter?

Don't get all wrapped up about it. The powders used in commercial ammo probably aren't the same ones we can buy for reloading anyway. The exact makeup is proprietary information. Don't worry about it.

I will just put that this refers to the weight of the bullet. Lighter bullets fly faster..ect.

Lighter bullets don't necessarily fly faster. If you look in a reloading manual, for the same caliber bullet a lighter bullet typically uses a heavier powder charge. Don't try to summarize the performance of any bullet based on weight alone. A modern cartridge is a system; the combination of a primer, a powder, and a projectile. Change any one of them and the cartridge performs differently.

I will add these things, and do my research to learn more about these tip types. I think for common use for me atleast with my 9MM i will probably stick with round tip for target and hollow point for defense

Good choice. FMJ for practice and JHP for self sefense is what most people use.

There is another projectile type that hasn't been mentioned yet: semi-wadcutter.

 

[hartcreek]

3c) Projectile TMJ --> stands for total metal jacket. This is basically the same thing as FMJ except with TMJ the bottom of the bullet is also covered in the copper material


Trunicated Metal Jacket

A trunicated bullet is a bullet with a cone with a flat tip

 

[Cheapshooter]

Is CCI the only major company that does aluminum. What would be the advantage/dissadvantage of aluminum over steel or brass?

I believe Blazer is the only aluminum case ammo. The only advantage is lower cost. Disadvantages, some say they can stick in the chamber, and the extractor will rip out of the rim. I personally haven't had that happen. The only other disadvantage doesn't concern you at this time. The aluminum cases are not reloadable.

Ok this can get confusing fast. In general, when I am selecting ammo at the store is this something I have to worry about "faster burning..ect.." Do they even list this on the box? How do I chose which is best? --> Is it best for general purposes to assume its standard? I get what you are saying that different companies use different powder types which can burn at different rates. I am just not sure if this is something that I would need to get wrapped up in since i wont ever be a competition shooter?

No, it isn't anything you will know, nor does it matter. As long as the ammo functions properly in your gun. Some companies have the velocity marked on the box, others do not. A look through their catalogs will tell you. Some online sites like http://www.bing.com/search?pc=AMAZ&form=AMAZWB&setmkt=en-US&q=midwayusa Will list ballistic information for ammo they sell
With FMJ range ammo, velocities will be the same, or very close from brand to brand for the same bullet weight.

I will just put that this refers to the weight of the bullet. Lighter bullets fly faster..ect.

That would be a general rule of thumb.

I will add these things, and do my research to learn more about these tip types. I think for common use for me atleast with my 9MM i will probably stick with round tip for target and hollow point for defense

Yes, but, you also need to shoot some with HP defensive ammo on the range. Two reasons, to make sure your gun functions 100% reliably with your choice of defensive ammo, and to make sure it hits acceptably close to where your practice ammo hits.

 

[reddog81]

The beginners guide to reloading ammunition would be a good book for you to read. It does an excellent job covering the basics of the topics you are interested in. It only cost 10.99 on amazon and contains all the info you are looking for.

Also there is a 4th component to any loaded round - the primer. This is what ignites the powder. The primer is the round piece on the rear the the cartridge that is struck by the firing pin. If you're only buying factory ammo it's not that important but it is a major component none the less.

 

[Cheapshooter]

Trunicated Metal Jacket

A trunicated bullet is a bullet with a cone with a flat tip

The OP was correct by the majority of common definition sources.
http://ammo.net/bullet-type/total-metal-jacket-tmj

A bullet with a flat nose, cone shape is a truncated cone bullet.

"truncated cone
noun
:a cone section or pyramid lacking an apex and terminating in a plane usu. parallel to the base"
It can be a truncated cone solid bullet or TCSB, or a truncated cone hollow point or TCHP. It can also be known as JTC for Jacketed Truncated Cone

 

[Evil Monkey]

I just want to address the casing material......


Brass
---The physical properties of brass allows it to be practically a perfect casing material. The usual cartridge brass casing is made up of 70% copper and 30% zinc (minus trace material...). Brass exhibits good obturation, excellent lubricity, and great elasticity. It's ductility is high, resisting fracturing and splitting. It's elasticity allows it to retract quickly after pressure has dropped. Brass can be used in a variety of operating systems without ill effect.

Steel
---Steel casings have limitations in certain firearm operating systems, particularly those casings who initial casing geometry was based on the properties of brass (ie: 5.56mm and 7.62mm nato). Generally speaking, steel casings work best in blowback and delayed blowback firearms. The reason why they work very well in blowback firearms is because of steels poor obturation ability. Steel casings do not obturate evenly, allowing gaps between the chamber walls and the casing. It's as if it is "self fluting". Simply put, the speed at which casings in blowback and delayed blowback weapons are (self) extracted doesn't allow the lack of elasticity of steel to pose a problem (sticking), since blowback weapons generally run quite violently. In locked breach firearms, the operational forces are much lower, so the non-elastic steel casing clinging on to the chamber wall now poses a problem. In order for steel casings to work well in locked breach firearms, they need to be of low pressure, which is closely relative on how thick the case walls are to be. They also need to have a sufficient taper in order to break the seal and allow for reliable extraction.

Aluminum
---Aluminum casings are opposite of steel casings. Technically these are alloys, not straight aluminum. In any way, aluminum casings should never be used in blowback or delayed blowback weapon. Nor should it be used in any firearm with an unsupported chamber. Aluminum casings are much weaker in shear strength compared to the other two materials and are more likely to rupture if there is extraction while high pressure is still being exerted. At best, you'll have fail to ejects due to slow bolt velocity as a result of the casing sticking to the chamber walls and retarding the "blowback" effect. The cause of this is the lack of timely case wall retraction as a result of material heat management and physical properties of the aluminum casing under pressure.

 

[carguychris]

Another significant issue to consider when looking at case material is corrosion.

Steel- as virtually everyone knows- rusts quite badly if it's unprotected. To prevent this, most steel cases are coated with lacquer or varnish, while a few types, notably Silver Bear and Warsaw Pact military surplus, are plated with another type of metal. (FWIW the "brass" cases on vintage Russian military rifle cartridges are usually steel that's plated with a copper alloy that has a brass-like color. Their pistol cartridges, on the other hand, generally have actual all-brass cases.) A lacquer or varnish coating can cause problems in certain firearms; I don't believe that it will actually and truly melt as asserted by some shooters, but I HAVE felt it get sticky when hot, I've seen small amounts scraped off the case while loading or feeding, and I've also seen cartridges with uneven and lumpy coatings.

Brass will also corrode quite badly if it's left in a humid environment long enough, which is why some types of self-defense ammo have nickel-plated cases, while FMJ practice ammo rarely does. The underlying assumption is that SD ammo may stay inside a holstered firearm for many months or even years, while most practice ammo will stay in the box until shortly before it's fired.

Corrosion is not a big problem with most alloys of aluminum, which is why you frequently see unpainted aluminum items used in outdoor applications, e.g. American Airlines jets before they introduced their white paint scheme last year. Aluminum DOES actually oxidize, but the oxide is thin and slippery and can be wiped off quite easily; it shouldn't pose a problem feeding in a firearm.

Asides from corrosion, there are also two other major issues with steel-case ammo.

• Most Russian steel-case ammo- i.e. most steel-case ammo, period- has bullets with cores or jackets made wholly or partially from mild steel. Notably, Tulammo has mild steel jackets with a thin copper coating to make them look like copper-jacketed FMJ. The steel in the bullets causes accelerated barrel wear and also damages steel target hangers, steel-plate targets, and steel backstops to a much greater degree than copper-jacketed bullets; this last factor is the REAL reason why an increasing number of public ranges ban steel-case ammo, contrary to the assertion by the guy at the gun store that "they can't sell the cases". (Brass scrap is worth more that steel and steel cases can't be sold to handloaders, but to a shooting range, this is generally a minor issue compared to the money they lose when range lanes are shut down for weeks because of damaged range equipment.)
• They are generally made with harder primers than American or Western European ammo. This may cause intermittent failures to fire in some firearms.

 

[Jim Watson]

Actually, most of the aluminum cased ammunition on the market recently has been Federal branded. Considering that Federal and CCI are now owned by Alliant, that is a distinction without a difference.
There was also some aluminum ammunition with Nyclad bullets under the Herter's label. Since the Nyclad bullet was a Federal product, I conclude this was a branding ploy and the ammo came out of the same factory.

If the OP wishes to sound more sophisticated, he will refer to cartridge cases.
Sausages have casings.

Likewise "projectile grains" is not conventional usage. We go ahead and call them bullets and speak of "bullet weight," only getting down to the grains when describing a specific item, as "124 grain (abbreviated gr) TMJ."

TMJ is a Speer trademark for their bullets with jacket metal applied by electroplating instead of mechanical deep drawing. There are a lot of other plated bullets on the market now, but few if any are so thickly plated as to equal the TMJ or a conventional jacket.

 

[Aguila Blanca]

3c) Projectile TMJ --> stands for total metal jacket. This is basically the same thing as FMJ except with TMJ the bottom of the bullet is also covered in the copper material


Trunicated Metal Jacket

A trunicated bullet is a bullet with a cone with a flat tip

Any time I have seen the abbreviation TMJ, it has stood for Total Metal Jacket, which is (as the OP wrote) a full metal jacket that also encloses the base of the bullet.

 

[James K]

The original purpose of FMJ bullets in auto pistols was so they didn't distort in feeding, like lead bullets could do, and hang up the gun. Other benefits, like deeper penetration, are secondary.

Just to confuse: An old term for full metal jacket is "metal case" or sometimes "steel case"; this refers to the bullet, not to the cartridge case, so can be confusing. This is not the same as "steel core", which refers to the material at the center of the bullet. Steel core was usually used where lead was expensive or unobtainable, as in wartime. A mild steel core is not the same thing as "armor piercing", which indicates a bullet (usually a rifle bullet) with a very hard steel core.

Jim

 

[hartcreek]

How do you figure that aluminum cases should not be used in blowback design pistols?

Now as for reloading aluminum cases....it can be done once or twice as I have done it.

 

[Snyper]

How do you figure that aluminum cases should not be used in blowback design pistols?

Aluminum isn't as slick as brass, and doesn't spring back as well, which could lead to failure to extract/eject

 

[Evil Monkey]

How do you figure that aluminum cases should not be used in blowback design pistols?

historically they've always been trouble in blowback guns.

Very high ductility and malleability give it low shear strength, making it less able to handle pressure/force against the material. Considering blowback guns will have the casing being pushed out while there is still relatively high pressure in the chamber produces situations where the aluminum casing is more likely to rupture at the case web.

The thermal expansion coefficient of aluminum alloys versus cartridge brass is what causes the "sticking" effect. Aluminum alloys used in cartridge casings are terrible at storing heat. The material expands at lower temperatures and after attaining thermal equilibrium between the chamber walls and casing, the aluminum casing takes a longer time to contract. The gas pushing against the casing to cycle the bolt in a blowback operated system must contend with this. Sometimes the bolt doesn't get the necessary velocity to cycle correctly and thus, you get a fail to eject, because the bolt didn't have enough velocity to strike the casing against the ejector to get rid of it.